The present invention relates to a palletizer for automatically loading bundles of newspapers on pallets.
Automatic pallet loaders are well known. These loaders receive a stream of articles, orient them properly, form them into rows, group the rows into layers and deposit the layers sequentially on a pallet. Prior palletizers of this type have been used to palletize bundles of newspapers.
Palletizing bundles of newspapers presents problems because of the size and shape of the newspaper bundles. Newspapers are usually folded to a rectangular shape about 12 by 15 inches and a stack of such newspapers has a generally rectangular plan view. However, newspaper bundles do not form a uniform square stack in side or end views. This is due to the fact that the strap for the bundle compresses the center portion of the stack. As a result the bundles may "butterfly" in side view and may have rounded corners in an end view. A folded newspaper is necessarily slightly thicker along the folded edge opposite from the headline, with the result that a stack of newspapers has a trapezoidal profile or elevation view. Although a compensated stack made with half of the folded edge facing one way and half the folded edges facing the other way can make the stacks more nearly rectangular, the rounded corners and butterfly effect remain. The irregular shape of newspaper bundles make them difficult to palletize automatically.
Prior pallet loaders for handling newspaper bundles have not been effective to stack the irregularly shaped newspaper bundles in a fast operation. Moreover, they have not been capable of forming a top layer of bundles having a different number of bundles than the other layers.